Nowadays, the trends of designing electronic products are toward slimness. For example, the thickness of the motor used in the electronic product is gradually reduced. Consequently, many benefits such as slimness, low noise and high efficiency could be achieved.
FIG. 1A is a schematic exploded view illustrating a stator assembly of a conventional motor. FIG. 1B is a schematic cross-sectional view illustrating the stator assembly of FIG. 1A. For example, the brushless motor 1 shown in FIGS. 1A and 1B is a slim reel-type brushless motor disclosed in U.S. Pat. No. 6,285,108. The brushless motor 1 comprises a magnetic conductive tube 10, a lower pole plate 11 and a bobbin 12. The magnetic conductive tube 10 is made of magnetic material. Moreover, an upper pole plate 101 is extended from an end of the magnetic conductive tube 10. The lower pole plate 11 is also made of magnetic material. The bobbin 12 is arranged between the magnetic conductive tube 10 and lower pole plate 11. After the magnetic conductive tube 10, the lower pole plate 11 and the bobbin 12 are combined together, a winding space is defined by the upper pole plate 101, the lower pole plate 11 and the bobbin 12. In addition, a coil 13 is wound on an outer surface of bobbin 12 and within the winding space.
In the brushless motor 1, the bobbin 12 is made of insulation material and the coil 13 is wound on the bobbin 12. When the brushless motor 1 is designed, only the winding structure and the insulating function are taken into consideration. However, the structures of positioning the stator, the coil, the driving circuit and other components are not designed.
FIG. 2 is a schematic exploded view illustrating a stator assembly of another conventional motor. For example, the motor 2 of FIG. 2 is a miniature motor disclosed in U.S. Pat. No. 6,787,964. As shown in FIG. 2, the miniature motor 2 comprises a first coil seat 21, a second coil seat 22 and a coil 23. Both of the first coil seat 21 and the second coil seat 22 are made of conductive material. The first and second coil seats 21, 22 comprise ring-shaped bottom plates 210 and 220, respectively. Moreover, plural outer teeth 211 are protruded from and arranged around the outer periphery of the bottom plate 210, and plural outer teeth 221 are protruded from and arranged around the outer periphery of the bottom plate 220. Since the bottom plates 210 and 220 are ring-shaped, the bottom plates 210 and 220 have corresponding central openings. Moreover, plural inner teeth 212 are protruded from the inner periphery of the bottom plate 210 and arranged around the central opening of the bottom plate 210, and plural inner teeth 222 are protruded from the inner periphery of the bottom plate 220 and arranged around the central opening of the bottom plate 220. For combining with the first and second coil seats 21, 22, the outer teeth 211 of the first coil seat 21 and the outer teeth 221 of the second coil seat 22 are staggered, and the inner teeth 212 of the first coil seat 21 and the inner teeth 222 of the second coil seat 22 are staggered. In addition, the preformed coil 23 is accommodated within a space between the first and second coil seats 21, 22. For electrically isolating the coil 23 from the first and second coil seats 21, 22, the coil 23 should have a specially-designed insulation surface.
The miniature motor 2 has small volume. However, the structures of positioning the stator, the coil, the driving circuit and other components are not designed. Since some drawbacks are caused by the lack of the positioning structures, the process of assembling the miniature motor 2 is time-consuming and labor-intensive. That is, the fabricating cost is increased.
In some other conventional technologies, an I-shaped bobbin is employed to wind the coil and assemble with the upper pole plate and the lower pole plate. When the I-shaped bobbin is designed, only the winding structure and the insulating function are taken into consideration. Similarly, the structures of positioning other components are not designed. Moreover, the winding space of the I-shaped bobbin is restricted by the upper pole plate and the lower pole plate. Consequently, the operating efficiency of the motor could be reduced.
Conventionally, the bobbin is combined with the stator or the driving circuit through a percussion riveting means or a dispensing means. However, the assembling process is complicated and time-consuming, and the product quality is adversely affected by the I-shaped bobbin.
Therefore, there is a need of providing an improved slim reel-type brushless motor and an insulation seat thereof in order to overcome the above drawbacks.